What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Brake Pedal Travel

SeanB

Well Known Member
Hi,
I just got my rudder cables attached to my pedals. All is in the most forward mounting location. Grove adjustable master cylinders. Pedals have a slight forward tilt when neutral compared to the tubular frame. All feels about right to my foot.

Question: How far do the Grove brake pedals travel when fully engaged? I can fully move the rudder to each stop no problem. I don’t have fluid in the system yet, so the pedals will go quite far and hit the firewall when using brakes, plus one makes contact with a FF pass thru. Hoping I don’t have to relocate that. Seems there are no positive stops with these cylinders.

Thanks for any help.
 
I have the Grove master cylinders, and love them! Once you get fluid in the system, and make sure there is no air in the system, the brake pedals don't move very far at all when you apply the brakes. I haven't measured the travel at the top of the brake pedal, but I would guess it is between !/2 inch to one inch. Maybe less.

When you add fluid, best to pump it in from the "bottom up", that way all the air will go out through the brake fluid reservoir.
 
Thanks, Pete! That's quite a bit less travel than I expected and seems to make my setup work pretty well. Will follow your advice for adding brake fluid from the bottom.
 
Hoping someone else can chime in with an actual measurement, as I am not able to access my plane to get an actual measurement for you. I'd hate for you to continue with just my "guesstimate" here.
 
First time to bleed my brakes on RV 7A

I noticed that my left brake moved quite a bit and did not seem to have the same feel as my right one. I bought and installed new brake pads and noted the old ones were worn about 70%. Did not solve the problem so I need to bleed the brakes.

I believe at this point that were I to crawl under the instrument panel to attempt to bleed the brakes they would have to cremate the entire plane with my body as my body would not be coming out.....

I cannot get a good picture in my mind as to how the single reservoir supplies two independent brake systems but see nothing in the schematics that leads me to believe pressure from the bottom can get through the pedal mounted master cylinder to exit the reservoir. Perhaps there is a one way valve involved that I am not seeing else when you push on the brake it would go equally to the reservoir and to the other master cylinder as well as the cylinder in the main...

I am building a pressure bleeder with a pump oil can and hope [yes I know that hope is NOT a plan] that I can pressure bleed from each brake at the mains and catch the overflow from the reservoir as I do each side. Since it has a threaded plug perhaps I can get a fitting to attach a hose so that I can catch the overflow in a container. Following this procedure seems as if it will flush all the old brake fluid out to be replaced by my new fluid.

Any comments would help...
 
Dana,

Shouldn't be any need to get down under the instrument panel to bleed the brakes, other than to make sure the tops of the rudder pedals are all the way aft (i.e. no pressure on the master cylinders). Just to be sure, I use a bungee cord or a piece of cord attached to the top of each pedal and run it aft to the control stick, or some other anchor point. With this assured, fluid will flow uphill through the master cylinders to the reservoir.

Brake line routing includes a "T" below the reservoir which splits fluid to left and right brakes.

As you suggested, I attach a 1/8" hose nipple to the top of the reservoir with a tube running to a catch can, so I can pump away at the bottom without having to constantly go back up to view the fluid level in the reservoir.

Make sure you have a good tight connection at the bottom, at the caliper, with the hose from your brake fluid pumper, so that you are not introducing air at the bleeder valve on the caliper.
 
I'm told this works great! pressurized with shop air. Beats a pump bleeder or the oil can version.

Tom
 

Attachments

  • AMAZON BRAKE BLEEDER.jpg
    AMAZON BRAKE BLEEDER.jpg
    264.3 KB · Views: 225
Back
Top